Satellite-based communication systems are typically used to provide TV broadcast transmissions as well as other types of communication signals over a large geographical area, such as the contiguous 48 states of the U.S. In a typical satellite-based communication system, the satellite receives signals from a feeder Earth station and then re-transmits the signals to end user stations throughout a target area. Ideally, the satellite transmissions are intended to deliver an equitable level of signal power, known as the effective isotropic radiated power (EIRP), to every end user station within the satellite coverage area. One obstacle in achieving ideal EIRP coverage, however, is the adverse effect of localized signal path losses that are typically caused by weather-related conditions such as rain. That is, rain can attenuate transmitted signal strength to a degree that may result in poor quality reception or even a total loss of signal to an end user.
To overcome this problem, some satellite transmission systems have been equipped with power-distribution techniques that can enable the individual adjustment of power to the satellite output feed horns in order to boost the amount of power being transmitted to rain-affected areas. One power-distribution technique utilizes signal amplifiers connected to hybrid matrices in order to share amplifier resources for a number of feed horns. In this type of power pooling arrangement, the amplifiers are generally configured to have identical gain and phase parameters in order to achieve optimal performance of the system. However, if these gain and phase parameters are not held constant, cross talk can occur between the output ports, and a loss of output power may result.
The stability of the amplifier gain and phase parameters can be adversely affected by influences such as changes in temperature, aging of associated internal and external components, power supply voltage drift, and so forth. In addition, the phase and gain parameters of the line lengths between the amplifiers and the hybrid matrices can also affect the performance of the power pooling arrangement.
Accordingly, it is desirable to provide a phase and gain stabilization system that maintains constant phase and gain parameters for amplifiers in a power pooling arrangement over the frequency band of interest. In addition, it is desirable to provide an adjustment capability to compensate for phase and gain differences that may be caused by unequal line lengths between the amplifiers and their associated components. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.